1. Field of the Invention
The present invention relates to a camera for preventing camera shake.
2. Related Background Art
As prior art, for example, a technique for indicating a camera shake in the form of, e.g., a bar graph proportional to the shake amount together with a shake amount allowable range before a photographing operation, and a technique for indicating a degree of shake after a photographing operation are known (Japanese Laid-Open Patent Application No. 2-126251).
Also, for a case when the shake amount exceeds an allowable range, a technique for causing, e.g., the bar graph to flicker, or generating a tone to warn a camera shake state to a photographer, is known (Japanese Laid-Open Patent Application No. 2-126250).
Also known is an anti-shake camera, which comprises a shake sensor and a shake correction lens, and moves the shake correction lens along a plane perpendicular to the optical axis on the basis of the shake amount detected by a shake sensor so as to prevent a camera shake. The shake correction lens is restricted by a mechanical or electrical stopper means so as to be movable within a positional range in which optical image quality is not deteriorated or deteriorated only slightly, thereby determining a correction range.
However, in the above-mentioned prior art, only the magnitude of the shake amount is indicated before a photographing operation, and the moving direction of the center of shake is unknown. When the center of shake moves, the shake correction lens may reach the end of the correction range.
More specifically, when the center of shake is located at the end of the correction range upon releasing of a shutter, since the shake correction lens moved in the shake correction direction is stopped by the stopper, and a camera shake cannot be satisfactorily corrected, a photographed picture has a blurred image even if the magnitude of shake is detected before the photographing operation.
In general, in a hand-held photographing operation, especially when a lens having a large focal distance is used or when a low shutter speed is selected, a camera shake easily occurs, and image quality of a picture is deteriorated. In order to prevent this, a camera shake state is informed to a photographer, thereby preventing a blurred picture. As such an information means, an alarm tone may be generated, or a vertical or horizontal bar representing the shake amount may be indicated in a finder.
With the above-mentioned camera-shake alarm device, a camera shake state can be confirmed. However, how to suppress a camera shake is not easily understood. When the device generates an alarm tone, the alarm tone may undesirably be generated in a situation requiring quietness.
Furthermore, in conventional cameras, various alarm indications are made. As the most popular one of these alarm indications, a camera shake alarm indication of a camera is known. In the conventional camera shake alarm indication, a shutter speed indication is caused to flicker, or an alarm tone is generated. Furthermore, a pattern representing a camera shake is provided as liquid crystal indication segments, and is caused to flicker on a liquid crystal screen (LCD) arranged on the casing of the camera or in a finder (e.g., Japanese Patent Publication No. 62-37771).
A beginner cannot often recognize what an alarm means based on the above-mentioned flickering indication of a shutter speed or the tone. An alarm by means of flickering indication of the special pattern on the LCD cannot be identified if the pattern is complicated and small, although it allows easy recognition as compared to other alarm methods. Conversely, if the pattern is large, it undesirably decreases a space for other indications. These alarm indications can inform a camera shake state, but cannot inform a degree of camera shake to a photographer. In addition, the photographer can know a camera shake state, but cannot understand how to suppress the camera shake.